The applicability of arterial pulse oximetry to dental pulp was demonstrated using in vitro and in vivo measurements. First, porcine blood of known oxygen saturation (SO 2 ) was circulated through extracted human upper incisors, while transmitted-light plethysmography was performed using three different visible wavelengths. From the light intensity waveforms measured in vitro , a parameter that is statistically correlated to SO 2 was calculated using the pulsatile/nonpulsatile component ratios of two wavelengths for different SO 2 . Then, values were measured in vivo for living incisors, and the corresponding SO 2 values were calculated using the results of in vitro measurements. The estimated SO 2 values of the upper central incisors measured in vivo were from 71.0 to 92.7%. This study showed the potential to measure the oxygen saturation changes to identify the sign of pulpal inflammation.
Kakino, S., Kushibiki, S., Yamada, A., Miwa, Z., Takagi, Y., & Matsuura, Y. (2013). Optical Measurement of Blood Oxygen Saturation of Dental Pulp. ISRN Biomedical Engineering, 2013, 1–6. https://doi.org/10.1155/2013/502869